Svelte vulnerabilitiesSvelte: known vulnerabilities and safe versions
npm: svelte
Svelte has 16 known vulnerability records: 12 in the npm advisory data (GitHub Advisory Database via OSV, the same source npm audit uses) and 4 only in Retire.js (CDN builds and advisories without a CVE). The latest release is 5.57.2 (endoflife.date).
By branch: 5.x is safe from 5.55.7; 4.x has no fixed release in the records; 3.x has no fixed release in the records; 2.x has no fixed release in the records.
Vulnerabilities and safe version by branch
Safe version: on that branch, this release and every later one (up to the branch's latest release, where known) fall outside every known record's range. Candidates are only the records' own fixed versions and the branch's latest release; "No fix" means moving off the branch.
| Branch | Support | Latest on branch | Records | Safe version |
|---|---|---|---|---|
| 5.x | Supported | 5.57.2 | 11medium | 5.55.7 |
| 4.x | Ended (October 19, 2024) | 4.2.20 | 7medium | No fix |
| 3.x | Ended (June 22, 2023) | 3.59.2 | 10high | No fix |
| 2.x | Ended (April 21, 2019) | 2.16.1 | 10medium | No fix |
| 1.x | Ended (April 19, 2018) | 1.64.1 | 10medium | No fix |
Records
Newest first. Ranges are the record's own data; several ranges mean separate fixes per branch.
CVE-2026-425992026-06-09
Cross-site scripting via spread attributes in Svelte SSR
Affected versions: < 5.55.7
medium 5.1
Fixed in: 5.55.7
CVE-2026-425732026-06-09
Svelte: XSS via DOM Clobbering of Internal Framework State
Affected versions: < 5.55.7
medium 5.3
Fixed in: 5.55.7
CVE-2026-425672026-06-09
Svelte: ReDoS in `<svelte:element>` Tag Validation
Affected versions: >= 5.51.5, < 5.55.7
medium 5.9
Fixed in: 5.55.7
CVE-2026-279022026-02-25
Svelte Vulnerable to XSS via HTML Comment Injection in SSR Error Boundary Hydration Markers
Affected versions: >= 5.53.0, < 5.53.5
medium 5.3
Fixed in: 5.53.5
CVE-2026-279012026-02-25
Svelte vulnerable to XSS during SSR with contenteditable `bind:innerText` and `bind:textContent`
Affected versions: < 5.53.5
medium 5.3
Fixed in: 5.53.5
CVE-2026-271252026-02-20
Svelte SSR attribute spreading includes inherited properties from prototype chain
Affected versions: < 5.51.5
medium 5.3
Fixed in: 5.51.5
CVE-2026-271222026-02-20
Svelte SSR does not validate dynamic element tag names in `<svelte:element>`
Affected versions: < 5.51.5
medium 5.1
Fixed in: 5.51.5
CVE-2026-271212026-02-20
Svelte affected by cross-site scripting via spread attributes in Svelte SSR
Affected versions: < 5.51.5
medium 5.1
Fixed in: 5.51.5
CVE-2026-271192026-02-20
Svelte affected by XSS in SSR `<option>` element
Affected versions: >= 5.39.3, < 5.51.5
medium 5.1
Fixed in: 5.51.5
CVE-2025-152652026-01-15
Svelte 5.46.0 - Hydratable Key Script-Breakout XSS (SSR)
Affected versions: >= 5.46.0, < 5.46.4
medium 5.3
Fixed in: 5.46.4
CVE-2024-450472024-08-30
Potential mXSS vulnerability due to improper HTML escaping in svelte
Affected versions: < 4.2.19
medium 6.1
Fixed in: 4.2.19
medium 6.1
Fixed in: 3.49.0
EPSS 1.4%
no CVE
XSS
Affected versions: < 3.46.5
medium
Fixed in: 3.46.5
no CVE
XSS
Affected versions: < 2.9.8
medium
Fixed in: 2.9.8
In Svelte's server-side rendering, a textarea element with a two-way bound value does not have its content properly escaped in the rendered HTML. Attacker-controlled values can break out of the textarea context and inject arbitrary HTML or
Affected versions: >= 3.0.0, < 3.59.2
high
Fixed in: 3.59.2
Svelte's hydratable feature (experimental) does not properly stringify promise values when hydrating, potentially leading to XSS. Applications using hydratable with attacker-controlled input where a synchronous value is followed by a promis
Affected versions: >= 5.46.0, < 5.55.7
medium
Fixed in: 5.55.7
Sources and method
Ranges: GitHub Advisory Database (OSV npm export, daily) and Retire.js (Apache-2.0). Exploitation: CISA KEV, FIRST EPSS and exploit maturity from the Noroxi CVE database. Support dates: endoflife.date.
This page and the JavaScript library scan use the same matching rule: a row without bounds is not evidence, and versions are compared in one place. A record without a version range never counts as "affected" in the version check.
Data as of October 22, 2026.